Chapter 8 Lines overview 97Networking Configuration Guide• Avoid putting unsupervised loop start lines in a line pool. These lines can become unusable,especially when a remote user uses the line pool to make an external call.• To assign line pool access to telephones, select Configuration > Telephony > Dialing Plan >Line Pools.• To assign system-wide line pool access codes, select Configuration > Telephony > DialingPlan > General (not applicable to Bloc pools).• A telephone can be administered to search automatically for an idle line from several lines thatappear on the telephone. Assign a line pool as the prime line. When the user lifts the receiveror presses Handsfree, any one of the lines, if idle, can be selected by Automatic Outgoing Lineselection.• Changes in the settings for trunk type on a system that is in use can result in dropped calls.• When assigning lines to line pools, consider your network configuration. You can create aunified dialing plan by assigning lines to the same location to the same line pool on each ofyour systems. For example, if system A and system B each have TIE lines to system C, assignthe TIE lines to pool D on each of the systems. You cannot assign target lines to a line pool, asthey are incoming-only.Using loss packagesUse the loss package settings to select the appropriate loss/gain and impedance settings for eachline. The setting is based on the terminating switch type and the distance between BCM and theterminating switch.When measuring the distance from BCM to CO and from BCM to PBX systems, use 600 ohms asthe termination resistance setting.A loss of 4 dB corresponds to a cable length of approximately 2700 m (9000 ft).Table 12 Loss package settingsLossPackageReceiveLossTransmitLossImpedance Distance to switch/cable loss/terminatingswitchShort CO 0 dB 3 dB Short Short/<2 dB/BCM to COMedium CO 0 dB 0 dB TIA/EIA 464 Medium/>2 dB and <6 dB/BCM to COLong CO -3 dB 0 dB TIA/EIA 464 Long/>6 dB/BCM to COShort PBX 0 dB 0 dB Short Short/<2 dB/BCM to PBXLong PBX -3 dB 0 dB TIA/EIA 464 Long/>2 dB/BCM to PBXNote: Loss packages are not supported on the 4X16 combo.
